Bi-directional single-phase half-bridge rectifier for power quality compensation

A single-phase half-bridge rectifier with a capacitor clamped scheme is proposed. Four power switches and one flying capacitor are employed in the proposed rectifier. Bipolar and unipolar PWM control schemes are used to perform power factor correction and achieve low total harmonic distortion of line current. A neutral point voltage balance compensator, hysteresis current controller and DC link voltage regulator are used to balance neutral point voltage, to track line current command, and to maintain the constant DC bus voltage. The proposed control scheme and the circuit configuration can also perform a shunt active power filter operation to eliminate the harmonic currents and compensate the reactive power generated from the nonlinear load. Analytical and experimental results are presented to illustrate the validity and effectiveness of the proposed control scheme.